[Objective] This study was conducted to understand goat germplasm char- acteristics. [Method] With some 24-month-old males and females Tibet goats as experimental materials, a slaughter experiment was carried out to d...[Objective] This study was conducted to understand goat germplasm char- acteristics. [Method] With some 24-month-old males and females Tibet goats as experimental materials, a slaughter experiment was carried out to determine their slaughter performance, muscle quality and muscle nutritional components. [Result] The body weights of males and females before slaughter were (20.16±1.26) and (19.33±4.86) kg, respectively; the dressing percentages of males and females were (43.86±1.74)% and (44.08±5.46)%, respectively; the meat percentages were (32.43± 1.52)% and (32.72±3.97)%, respectively; and the meat production rates of carcass were (73.28±0.09)% and (73.16±0.85)%, respectively. There were less differences in carcass measurements, carcass segmentation, muscle quality, muscle fiber charac- teristics, muscle nutritional components, muscle mineral contents and heavy metal contents between males and females, while eye muscle area and hind leg meat weight of males were significantly higher than those of females. In muscles of males and females, 18 amino acids were detected totally, EAA/TAA values were (39.23±0.24)% and (38.70±0.15)%, respectively, and EAA/NEAA values were (64.73± 0.65)% and (63.17±0.41)%, respectively. [Conclusion] This study lays a foundation for overall understanding of germplasm characteristics of Tibetan goats.展开更多
[Objective] The aim was to discuss the resource characteristics of Danba goat. [Method] Three male and three female goats of twelve-month-old Danba goat were selected to slaughter,and their slaughter performance, musc...[Objective] The aim was to discuss the resource characteristics of Danba goat. [Method] Three male and three female goats of twelve-month-old Danba goat were selected to slaughter,and their slaughter performance, muscle qulity and mus- cle nutrients were determined. [Result] The pre-slaughter weights, dressing percent- ages, meat percentages and carcass meat production rates of the male and female Danba goats were (25.83±1.04) and (18.50±2.29) kg, (45.18±0.78)% and (38.89± 2.08)%, (33.76±1.4)% and (28.59±1.99)%, and (74.30±0.85)% and (74.08±0.65)%, respectively. The carcass length, carcass hind leg circumstance, carcass hind leg length, lumbar muscle thickness, hind leg meat yield, shoulder muscle yield and breast meat yield of male goats were significantly higher than those of female goats (P〈0.05), and no significant differenceswere found in other carcass size and carcass segmentation indices between male and female goats (P〉0.05). There were small differences in muscle fiber properties, muscle quality, muscle nutritional composition, muscle mineral content and muscle heavy metal content between male and female goats (P〈0.05). A total of 18 kinds of amino acids were detected in the male and female goats. The EAA/TAAs and EANNEAAs of male and female goats were (39.56±0.26)% and (39.48±0.66)%, and (65.45±0.71)% and (65.43±1.80)%, respec- tively. [Conclusion] This study will provide the basis for the understanding of the resource characteristics of Danba goat.展开更多
Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical,...Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical, through oxidative esterification over Au-based catalysts. Detailed experimental studies showed that Au on amphoteric supports with appropriate strength and balanced ratio of acid and base sites can facilitate the desired oxidative-esterification pathway without accelerating undesired aldol-condensation or Cannizzaro reactions. In particular, hydroxyapatite (with a Ca/P ratio of 1.62) supported Au achieved 87% selectivity to methyl pyruvate at an acetol conversion of 62%.展开更多
Seed‐assisted low alkalinity gel system was developed to explore the organic‐free synthesis of MORzeolite.MOR nanoassemblies with Si/Al ratio(SAR)up to 9.4 and high solid yield(84–94%)weresuccessfully obtained unde...Seed‐assisted low alkalinity gel system was developed to explore the organic‐free synthesis of MORzeolite.MOR nanoassemblies with Si/Al ratio(SAR)up to 9.4 and high solid yield(84–94%)weresuccessfully obtained under controlled low alkalinity conditions.Characterization results demonstratethat the acid strength increases in parallel with the SAR,while the total acid amount and theproton distribution in the main channels and the side pockets are similar for the samples.The protondistribution in the H‐MOR is not straightforwardly related to the Na+distribution in theas‐synthesized MOR,implying the transfer of the protons among the oxygen sites of framework Tatom.Relative to low‐silica samples I‐5.3 and I‐7.4,sample I‐9.4 displays the best mass transferperformance and accessibility of the acid sites by pyridine due to its relatively low Al density andmild dealumination degree.Correspondingly,sample I‐9.4(pyridine‐modified catalyst)shows thebest activity with ca.100%selectivity of methyl acetate(MAc)in the DME carbonylation reaction.The high steady MAc yield(6.8 mmol/g/h)over sample I‐9.4 suggests the promising application ofMOR nanoassemblies synthesized by this economical organic‐free strategy.展开更多
Gamma-aminobutyric acid (GABA) and glutamate are two important amino acid neurotransmitters widely present in the nervous systems of mammals, insects, round worm, and platyhelminths, while their receptors are quite ...Gamma-aminobutyric acid (GABA) and glutamate are two important amino acid neurotransmitters widely present in the nervous systems of mammals, insects, round worm, and platyhelminths, while their receptors are quite diversified across different animal phyla. However, the evolutionary mechanisms between the two conserved neurotransmitters and their diversified receptors remain elusive, and antagonistic interactions between GABA and glutamate signal transduction systems, in particular, have began to attract significant attention. In this review, we summarize the extant results on the origin and evolution of GABA and glutamate, as well as their receptors, and analyze possible evolutionary processes and phylogenetic relationships of various GABAs and glutamate receptors. We further discuss the evolutionary history of Excitatory/Neutral Amino Acid Transporter (EAAT), a transport protein, which plays an important role in the GABA-glutamate "yin and yang" balanced regulation. Finally, based on current advances, we propose several potential directions of future research.展开更多
Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane...Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the properties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.展开更多
Objective To investigate the relationship between geranylgeranyl pyrophosphate synthase (GGPPS) gene polymorphisms and bone response to alendronate in Chinese osteoporotic women. Methods A total of 639 postmenopaus...Objective To investigate the relationship between geranylgeranyl pyrophosphate synthase (GGPPS) gene polymorphisms and bone response to alendronate in Chinese osteoporotic women. Methods A total of 639 postmenopausal women with osteoporosis or osteopenia were included and randomly received treatment of low dose (70 mg per two weeks) or standard dose (70 mg weekly) of alendronate for one year. The six tag single nucleotide polymorphisms of GGPPS gene were identified. Bone mineral density (BMD), serum cross-linked C-telopeptide of type I collagen (β-CTX), and total alkaline phosphatase (ALP) were measured before and after treatment. GGPPS gene polymorphisms and the changes of BMD and bone turnover markers after treatment were analyzed. Results rs10925503 polymorphism of GGPPS gene was correlated to serumβ-CTX levels at baseline, and patients with TT genotype had significantly higher serum β-CTX level than those with TC or CC genotype (all P〈0.05). No correlation was found between polymorphisms of GGPPS gene and serum total ALP levels, as well as BMD at baseline. After 12 months of treatment, lumbar spine and hip BMD increased and serum bone turnover markers decreased significantly (P〈0.01), and without obvious differences between the low dose and standard dose groups (all P〉0.05). However, GGPPS gene polymorphisms were uncorrelated to percentage changes of BMD, serum total ALP, and β-CTX levels (all P〉0.05). Conclusion GGPPS gene polymorphisms are correlated to osteoclasts activity, but all tag single nucleotide polymorphisms of GGPPS gene have no influence on the skeletal response to alendronate treatment.展开更多
Peformance enhancing drugs are widely used today in different sport fields, and therefore the successful anti-doping activity should be based not only on regular doping controls, but also it should show the real alter...Peformance enhancing drugs are widely used today in different sport fields, and therefore the successful anti-doping activity should be based not only on regular doping controls, but also it should show the real alternative: how to replace the forbidden doping substances with legal and effective supplements. The paper deals with application proposition of protein concentrates, free AA (amino acids), HMB (hydroxy-methyle-butyrate), creatine and camitine. If the athlete is involved in strength and power sport (e.g. throwing events in track and field, olympic weightlifting etc.), the explosive and maximum strength is of primary importance. For strength athletes, these mentioned substances are those legal preparates, supplements, which can help effectively in performance improvement of sport results. The main reason is that using protein concentrates, AAs, HMB, creatine and camitine, the anabolic (and anticatabolic) effect will enhance the protein biosynthesis of the organism, improve the aerob and anaerob capacity of the athletes, activate and stimulate the own hormonal system. And the final result is creating higher loadability because of the faster recovery, and higher performance level on the competition. Of course, the athletes--as a minimum requirement--need an adequate nutrition (good balanced nourishment), as well, with appropriate application and supplementation of all vitamins and essential minerals.展开更多
A concept of potential crosslinking agent was introduced into the synthesizing process of highly oil-absorptive resin that is traditionally prepared by single chemical crosslinking.The resin was heated after manufactu...A concept of potential crosslinking agent was introduced into the synthesizing process of highly oil-absorptive resin that is traditionally prepared by single chemical crosslinking.The resin was heated after manufactured to obtain three-dimension network structure.The effects of potential crosslinking agent and the crosslinking conditions on the absorptive properties of resin were studied.The results showed that hydroxyl ethylacrylate got satisfied results,and the resin with it had good oil absorbency and oil retention.展开更多
The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol...The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol content, evaluation of reactive oxygen species (ROS) in liver mitochondria, Fe2+ chelating and 2,2-diphenyl-lpicrylhydrazyl (DPPH) scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE+ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested (15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous). Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2+ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.展开更多
ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS (PMMA: polymethyl methao- rylate) microspheres in acid-alkali solutio...ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS (PMMA: polymethyl methao- rylate) microspheres in acid-alkali solution, and the ZnO precursors, i.e. the ethanol solu- tions of (CHaCOO)2Zn and LiOH. The transmission electron microscope, X-ray diffraction, and thermogravimetric analysis results show that the feeding order of ethanol solutions of (CH3COO)2Zn and LiOH in the second swelling step has great influence on the loading efficiency and the size of ZnO nanoparticles, but little on their crystal form. The photolumi- nescence and UV-Vis absorption behavior of ZnO/PS microspheres show that the PS shell can effectively avoid the fluorescence quenching effect.展开更多
OBJECTIVE To observe the effect of all-trans retinoic acid (ATRA) on inducing human glioma MO59K cells differentiation and further explore the underlying molecular mechanisms.METHODS The expression of glial fibrilla...OBJECTIVE To observe the effect of all-trans retinoic acid (ATRA) on inducing human glioma MO59K cells differentiation and further explore the underlying molecular mechanisms.METHODS The expression of glial fibrillary acidic protein (GFAP) was detected by immunocytochemistry staining. The mRNA levels of GFAP, retinoid X receptor α(RXRα), p21 were examined by semi-quantitative RT-PCR analysis. Luciferase activity assay was performed in the COS-7, MO59K cells to measure p21 promoter transcription activity.RESULTS ATRA could significantly enhance the expression and mRNA level of GFAP by immunostaining and RT-PCR (P〈0.05). Simultaneously, the mRNA levels of RXRα and p21 were remarkably increased in dose-dependent manner by RT-PCR (P〈0.05). Furthermore, luciferase assay confirmed that ATRA and RXRα could transactivate p21 promoter in COS-7 and glioma cells (P〈0.05).CONCLUSION ATRA can induce differentiation of human glioma cells. The RXRα and p21 were activated during ATRAinduced differentiation process. This effect may be caused by directly RXRα-induced p21 gene transactivation. Our findings provide novel evidence for the future studies to explore the molecular mechanism of transcriptional regulation for glioma cell differentiation and cellular therapeutic approaches for glioblastoma.展开更多
Objective To determine whether all-trans retinoic acid (atR A) exerts an inhibitory effect on rats with pulmonary hypertension induced by monocrotaline.Methods All rats were given a single subcutaneous injection of ei...Objective To determine whether all-trans retinoic acid (atR A) exerts an inhibitory effect on rats with pulmonary hypertension induced by monocrotaline.Methods All rats were given a single subcutaneous injection of either monocrotaline (60 mg/kg) or saline.Monocrotaline-injected rats received either atRA (30 mg· kg-1· day-1) or saline through oral-gastro intubation. On Days 7, 14, 21, and 28 respectively after monocrotaline injection, cardiovascular catheters were inserted to examine the mean pulmonary artery pressure of rats in each group. Meanwhile, the matrix metalloproteinase-1 (MMP-1) mRNA expression and hydroxyproline content in the main pulmonary artery were determined by RT-PCR and chromornetry, respectively.Results The mean pulmonary artery pressure of rats in the model group increased significantly on day 21 and reached a peak on Day 28 compared with the control group (25.7+4.3 mm Hg vs 15.1 ± 1.5 mm Hg and 38.5 ± 6.4 mm Hg vs 16.4 ± 2.0 mm Hg, P < 0.01 ). MMP-1 mRNA overexpression was present on Day 14 (0.72 ± 0.15 vs 0.39 ± 0.08, P < 0.01 ) and was rapidly down-regulated on Day 21 and 28 compared with Day 14, but was still higher than that in the control. The hydroxyoroline content of the main pulmonary artery dropped significantly on Day 14 (4.01 ± 1.13 μg/mg vs 5.10 ± 0.91 μg/mg, P < 0.05)and increased significantly on Days 21 and 28 compared with the control, atRA inhibited the MMP-1 mRNA overexpression from Day 14 to Day 28 and reduced the hydroxyproline content (5.59 ± 0.70 μg/mg vs 7.96 ± 1.13 μg/mg and 7.77 ± 0.96 μg/mg vs 9.93 ± 1.27μg/mg, P < 0.01 ) and the mean pulmonary artery pressure compared with the model group ( 19.6 ± 3.2 mm Hg vs 25.7 ± 4.3 mm Hg and 26.3 ± 4.6 mm Hg vs 38.5±6.4 mm Hg, P<0.01).Conclusion atRA inhibits MMP-1 overexpression and the accumulation of collagen, which might elicit favorable geometric remodeling in rat pulmonary hypertension induced by monocrotaline.展开更多
Three new MOFs with the same components but different structures and magnetic behavior, {[Cu6(atr)6(H20)2(,u3- OH)2(SOa)5]'5.25H20}n (1), {[Cu2(atr)2(,t/-OH)2(SOa)].3H20}n (2), and {[CuT(atr)6(H2...Three new MOFs with the same components but different structures and magnetic behavior, {[Cu6(atr)6(H20)2(,u3- OH)2(SOa)5]'5.25H20}n (1), {[Cu2(atr)2(,t/-OH)2(SOa)].3H20}n (2), and {[CuT(atr)6(H20)6(fl3-OH)2(SOn)6].2H20}n (3) (atr= 4-amino-l,2,4-triazole), were respectively synthesized by diffusion reactions in the presence of different structure-directing agents. Complex 1 is a slightly spin-frustrated antiferromagnetic layer with sulfonate aggregated Cun6 clusters periodically ex- tended by ditopic sulfonate linkers. 2 is a grid-based coplanar sheet with hydroxyl group bridged -CuOCu- linear-chain inter- linked by pairs of p3-atr ligands, exhibiting strong antiferromagnetic interactions to lead to an S = 0 spin ground state at low temperature. In contrast, air-instable 3 has a ladder-like broad-ribbon structure constructed from triangular CuII3 cores and cen- trosymmetric CuII1 octahedra. Obviously, the variable Cun-ligand connectivity and the involving magnetic properties are sig- nificantly dominated by the cooperative and variable binding modes of the mixed sulfonate-atr ligands and bi-/tridentate bridging hydroxyl heterobridges.展开更多
Histone methylation is believed to provide binding sites for specific reader proteins, which translate histone code into biological function. Here we show that a family of acidic domain-containing proteins including n...Histone methylation is believed to provide binding sites for specific reader proteins, which translate histone code into biological function. Here we show that a family of acidic domain-containing proteins including nucleophosmin (NPM 1), pp32, SET/TAF 113, nucleolin (NCL) and upstream binding factor (UBF) are novel H3K4me2-binding proteins. These proteins exhibit a unique pattern of interaction with methylated H3K4, as their binding is stimulated by H3K4me2 and inhibited by H3K4mel and H3K4me3. These proteins contain one or more acidic domains consisting mainly of aspartic and/or glutamic residues that are necessary for preferential binding of H3K4me2. Furthermore, we demonstrate that the acidic domain with sufficient length alone is capable of binding H3K4me2 in vitro and in vivo. NPM1, NCL and UBF require their acidic domains for association with and transcriptional activation ofrDNA genes. Interestingly, by defining acidic domain as a sequence with at least 20 acidic residues in 50 continuous amino acids, we identified 655 acidic domain-containing protein coding genes in the human genome and Gene Ontology (GO) analysis showed that many of the acidic domain proteins have chromatin-related functions. Our data suggest that acidic domain is a novel histone binding motif that can differentially read the status of H3K4 methylation and is broadly present in chromatin-associated proteins.展开更多
Objective:This study aimed to clone and characterize the oxiranedicarboxylate hydrolase(ORCH) from Labrys sp.WH-1.Methods:Purification by column chromatography,characterization of enzymatic properties,gene cloning by ...Objective:This study aimed to clone and characterize the oxiranedicarboxylate hydrolase(ORCH) from Labrys sp.WH-1.Methods:Purification by column chromatography,characterization of enzymatic properties,gene cloning by protein terminal sequencing and polymerase chain reaction(PCR),and sequence analysis by secondary structure prediction and multiple sequence alignment were performed.Results:The ORCH from Labrys sp.WH-1 was purified 26-fold with a yield of 12.7%.It is a monomer with an isoelectric point(pl) of 8.57 and molecular mass of 30.2 kDa.It was stable up to 55℃with temperature at which the activity of the enzyme decreased by 50% in 15 min(T5015) of 61℃and the half-life at 50℃(t1/2,50℃) of 51 min and was also stable from pH 4 to 10,with maximum activity at 55℃and pH 8.5.It is a metal-independent enzyme and strongly inhibited by Cu2+,Ag+,and anionic surfactants.Its kinetic parameters(Km,kcat,and kcat/Km) were 18.7 mmol/L,222.3 s-1,and 11.9 mmol/(L s),respectively.The ORCH gene,which contained an open reading frame(ORF) of 825 bp encoding 274 amino acid residues,was overexpressed in Escherichia coli and the enzyme activity was 33 times higher than that of the wild strain.Conclusions The catalytic efficiency and thermal stability of the ORCH from Labrys sp.WH-1 were the best among the reported ORCHs,and it provides an alternative catalyst for preparation of L(+)-2,3-dihydrobutanedioic acid.展开更多
The association of the porcine Pitx2c gene with meat quality traits was investigated in the present study. A total of eight single nucleotide polymorphisms (SNPs) were found. Allele frequencies of four SNPs were fur...The association of the porcine Pitx2c gene with meat quality traits was investigated in the present study. A total of eight single nucleotide polymorphisms (SNPs) were found. Allele frequencies of four SNPs were further detected in four commercial breeds and eight Chinese indigenous breeds. Single SNP and meat quality associations were analyzed in a YorkshirexMeishan F2 population. The SNPs c.474C〉T (P〈0.01) and c.636C〉T (P〈0.05) showed a significant association with meat color (MCV1). The SNPs c,*37G〉A and c.*47G〉A were significantly associated with drip loss rate (DLR), water holding capacity (WHC) and meat color value (MCV1) consistently (P〈0.05). Linkage disequilibrium (LD) analysis revealed that the adjacent SNPs were in LD. Two major haplotypes were identified, and association analysis between haplotype combinations and meat quality indicated that the presence of two copies of haplotype 1 -CCGG- may improve meat quality.展开更多
基金Supported by Special Fund for Animal Husbandry Science and Technology in Sichuan Province~~
文摘[Objective] This study was conducted to understand goat germplasm char- acteristics. [Method] With some 24-month-old males and females Tibet goats as experimental materials, a slaughter experiment was carried out to determine their slaughter performance, muscle quality and muscle nutritional components. [Result] The body weights of males and females before slaughter were (20.16±1.26) and (19.33±4.86) kg, respectively; the dressing percentages of males and females were (43.86±1.74)% and (44.08±5.46)%, respectively; the meat percentages were (32.43± 1.52)% and (32.72±3.97)%, respectively; and the meat production rates of carcass were (73.28±0.09)% and (73.16±0.85)%, respectively. There were less differences in carcass measurements, carcass segmentation, muscle quality, muscle fiber charac- teristics, muscle nutritional components, muscle mineral contents and heavy metal contents between males and females, while eye muscle area and hind leg meat weight of males were significantly higher than those of females. In muscles of males and females, 18 amino acids were detected totally, EAA/TAA values were (39.23±0.24)% and (38.70±0.15)%, respectively, and EAA/NEAA values were (64.73± 0.65)% and (63.17±0.41)%, respectively. [Conclusion] This study lays a foundation for overall understanding of germplasm characteristics of Tibetan goats.
文摘[Objective] The aim was to discuss the resource characteristics of Danba goat. [Method] Three male and three female goats of twelve-month-old Danba goat were selected to slaughter,and their slaughter performance, muscle qulity and mus- cle nutrients were determined. [Result] The pre-slaughter weights, dressing percent- ages, meat percentages and carcass meat production rates of the male and female Danba goats were (25.83±1.04) and (18.50±2.29) kg, (45.18±0.78)% and (38.89± 2.08)%, (33.76±1.4)% and (28.59±1.99)%, and (74.30±0.85)% and (74.08±0.65)%, respectively. The carcass length, carcass hind leg circumstance, carcass hind leg length, lumbar muscle thickness, hind leg meat yield, shoulder muscle yield and breast meat yield of male goats were significantly higher than those of female goats (P〈0.05), and no significant differenceswere found in other carcass size and carcass segmentation indices between male and female goats (P〉0.05). There were small differences in muscle fiber properties, muscle quality, muscle nutritional composition, muscle mineral content and muscle heavy metal content between male and female goats (P〈0.05). A total of 18 kinds of amino acids were detected in the male and female goats. The EAA/TAAs and EANNEAAs of male and female goats were (39.56±0.26)% and (39.48±0.66)%, and (65.45±0.71)% and (65.43±1.80)%, respec- tively. [Conclusion] This study will provide the basis for the understanding of the resource characteristics of Danba goat.
基金supported by the National Natural Science Foundation of China(91545114,91545203,and 21576227)the 985 Program of the Chemistry and Chemical Engineering disciplines of Xiamen University~~
文摘Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical, through oxidative esterification over Au-based catalysts. Detailed experimental studies showed that Au on amphoteric supports with appropriate strength and balanced ratio of acid and base sites can facilitate the desired oxidative-esterification pathway without accelerating undesired aldol-condensation or Cannizzaro reactions. In particular, hydroxyapatite (with a Ca/P ratio of 1.62) supported Au achieved 87% selectivity to methyl pyruvate at an acetol conversion of 62%.
文摘Seed‐assisted low alkalinity gel system was developed to explore the organic‐free synthesis of MORzeolite.MOR nanoassemblies with Si/Al ratio(SAR)up to 9.4 and high solid yield(84–94%)weresuccessfully obtained under controlled low alkalinity conditions.Characterization results demonstratethat the acid strength increases in parallel with the SAR,while the total acid amount and theproton distribution in the main channels and the side pockets are similar for the samples.The protondistribution in the H‐MOR is not straightforwardly related to the Na+distribution in theas‐synthesized MOR,implying the transfer of the protons among the oxygen sites of framework Tatom.Relative to low‐silica samples I‐5.3 and I‐7.4,sample I‐9.4 displays the best mass transferperformance and accessibility of the acid sites by pyridine due to its relatively low Al density andmild dealumination degree.Correspondingly,sample I‐9.4(pyridine‐modified catalyst)shows thebest activity with ca.100%selectivity of methyl acetate(MAc)in the DME carbonylation reaction.The high steady MAc yield(6.8 mmol/g/h)over sample I‐9.4 suggests the promising application ofMOR nanoassemblies synthesized by this economical organic‐free strategy.
文摘Gamma-aminobutyric acid (GABA) and glutamate are two important amino acid neurotransmitters widely present in the nervous systems of mammals, insects, round worm, and platyhelminths, while their receptors are quite diversified across different animal phyla. However, the evolutionary mechanisms between the two conserved neurotransmitters and their diversified receptors remain elusive, and antagonistic interactions between GABA and glutamate signal transduction systems, in particular, have began to attract significant attention. In this review, we summarize the extant results on the origin and evolution of GABA and glutamate, as well as their receptors, and analyze possible evolutionary processes and phylogenetic relationships of various GABAs and glutamate receptors. We further discuss the evolutionary history of Excitatory/Neutral Amino Acid Transporter (EAAT), a transport protein, which plays an important role in the GABA-glutamate "yin and yang" balanced regulation. Finally, based on current advances, we propose several potential directions of future research.
文摘Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the properties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.
基金Supported by National Natural Science Foundation of China(81570802)National Key Program of Clinical Science(WBYZ2011-873)
文摘Objective To investigate the relationship between geranylgeranyl pyrophosphate synthase (GGPPS) gene polymorphisms and bone response to alendronate in Chinese osteoporotic women. Methods A total of 639 postmenopausal women with osteoporosis or osteopenia were included and randomly received treatment of low dose (70 mg per two weeks) or standard dose (70 mg weekly) of alendronate for one year. The six tag single nucleotide polymorphisms of GGPPS gene were identified. Bone mineral density (BMD), serum cross-linked C-telopeptide of type I collagen (β-CTX), and total alkaline phosphatase (ALP) were measured before and after treatment. GGPPS gene polymorphisms and the changes of BMD and bone turnover markers after treatment were analyzed. Results rs10925503 polymorphism of GGPPS gene was correlated to serumβ-CTX levels at baseline, and patients with TT genotype had significantly higher serum β-CTX level than those with TC or CC genotype (all P〈0.05). No correlation was found between polymorphisms of GGPPS gene and serum total ALP levels, as well as BMD at baseline. After 12 months of treatment, lumbar spine and hip BMD increased and serum bone turnover markers decreased significantly (P〈0.01), and without obvious differences between the low dose and standard dose groups (all P〉0.05). However, GGPPS gene polymorphisms were uncorrelated to percentage changes of BMD, serum total ALP, and β-CTX levels (all P〉0.05). Conclusion GGPPS gene polymorphisms are correlated to osteoclasts activity, but all tag single nucleotide polymorphisms of GGPPS gene have no influence on the skeletal response to alendronate treatment.
文摘Peformance enhancing drugs are widely used today in different sport fields, and therefore the successful anti-doping activity should be based not only on regular doping controls, but also it should show the real alternative: how to replace the forbidden doping substances with legal and effective supplements. The paper deals with application proposition of protein concentrates, free AA (amino acids), HMB (hydroxy-methyle-butyrate), creatine and camitine. If the athlete is involved in strength and power sport (e.g. throwing events in track and field, olympic weightlifting etc.), the explosive and maximum strength is of primary importance. For strength athletes, these mentioned substances are those legal preparates, supplements, which can help effectively in performance improvement of sport results. The main reason is that using protein concentrates, AAs, HMB, creatine and camitine, the anabolic (and anticatabolic) effect will enhance the protein biosynthesis of the organism, improve the aerob and anaerob capacity of the athletes, activate and stimulate the own hormonal system. And the final result is creating higher loadability because of the faster recovery, and higher performance level on the competition. Of course, the athletes--as a minimum requirement--need an adequate nutrition (good balanced nourishment), as well, with appropriate application and supplementation of all vitamins and essential minerals.
文摘A concept of potential crosslinking agent was introduced into the synthesizing process of highly oil-absorptive resin that is traditionally prepared by single chemical crosslinking.The resin was heated after manufactured to obtain three-dimension network structure.The effects of potential crosslinking agent and the crosslinking conditions on the absorptive properties of resin were studied.The results showed that hydroxyl ethylacrylate got satisfied results,and the resin with it had good oil absorbency and oil retention.
文摘The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol content, evaluation of reactive oxygen species (ROS) in liver mitochondria, Fe2+ chelating and 2,2-diphenyl-lpicrylhydrazyl (DPPH) scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE+ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested (15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous). Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2+ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.
文摘ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS (PMMA: polymethyl methao- rylate) microspheres in acid-alkali solution, and the ZnO precursors, i.e. the ethanol solu- tions of (CHaCOO)2Zn and LiOH. The transmission electron microscope, X-ray diffraction, and thermogravimetric analysis results show that the feeding order of ethanol solutions of (CH3COO)2Zn and LiOH in the second swelling step has great influence on the loading efficiency and the size of ZnO nanoparticles, but little on their crystal form. The photolumi- nescence and UV-Vis absorption behavior of ZnO/PS microspheres show that the PS shell can effectively avoid the fluorescence quenching effect.
基金the National Natural Science Foundation of China,Shandong Province Natural Science Foundation,Tianjin Natural Science Foundation
文摘OBJECTIVE To observe the effect of all-trans retinoic acid (ATRA) on inducing human glioma MO59K cells differentiation and further explore the underlying molecular mechanisms.METHODS The expression of glial fibrillary acidic protein (GFAP) was detected by immunocytochemistry staining. The mRNA levels of GFAP, retinoid X receptor α(RXRα), p21 were examined by semi-quantitative RT-PCR analysis. Luciferase activity assay was performed in the COS-7, MO59K cells to measure p21 promoter transcription activity.RESULTS ATRA could significantly enhance the expression and mRNA level of GFAP by immunostaining and RT-PCR (P〈0.05). Simultaneously, the mRNA levels of RXRα and p21 were remarkably increased in dose-dependent manner by RT-PCR (P〈0.05). Furthermore, luciferase assay confirmed that ATRA and RXRα could transactivate p21 promoter in COS-7 and glioma cells (P〈0.05).CONCLUSION ATRA can induce differentiation of human glioma cells. The RXRα and p21 were activated during ATRAinduced differentiation process. This effect may be caused by directly RXRα-induced p21 gene transactivation. Our findings provide novel evidence for the future studies to explore the molecular mechanism of transcriptional regulation for glioma cell differentiation and cellular therapeutic approaches for glioblastoma.
文摘Objective To determine whether all-trans retinoic acid (atR A) exerts an inhibitory effect on rats with pulmonary hypertension induced by monocrotaline.Methods All rats were given a single subcutaneous injection of either monocrotaline (60 mg/kg) or saline.Monocrotaline-injected rats received either atRA (30 mg· kg-1· day-1) or saline through oral-gastro intubation. On Days 7, 14, 21, and 28 respectively after monocrotaline injection, cardiovascular catheters were inserted to examine the mean pulmonary artery pressure of rats in each group. Meanwhile, the matrix metalloproteinase-1 (MMP-1) mRNA expression and hydroxyproline content in the main pulmonary artery were determined by RT-PCR and chromornetry, respectively.Results The mean pulmonary artery pressure of rats in the model group increased significantly on day 21 and reached a peak on Day 28 compared with the control group (25.7+4.3 mm Hg vs 15.1 ± 1.5 mm Hg and 38.5 ± 6.4 mm Hg vs 16.4 ± 2.0 mm Hg, P < 0.01 ). MMP-1 mRNA overexpression was present on Day 14 (0.72 ± 0.15 vs 0.39 ± 0.08, P < 0.01 ) and was rapidly down-regulated on Day 21 and 28 compared with Day 14, but was still higher than that in the control. The hydroxyoroline content of the main pulmonary artery dropped significantly on Day 14 (4.01 ± 1.13 μg/mg vs 5.10 ± 0.91 μg/mg, P < 0.05)and increased significantly on Days 21 and 28 compared with the control, atRA inhibited the MMP-1 mRNA overexpression from Day 14 to Day 28 and reduced the hydroxyproline content (5.59 ± 0.70 μg/mg vs 7.96 ± 1.13 μg/mg and 7.77 ± 0.96 μg/mg vs 9.93 ± 1.27μg/mg, P < 0.01 ) and the mean pulmonary artery pressure compared with the model group ( 19.6 ± 3.2 mm Hg vs 25.7 ± 4.3 mm Hg and 26.3 ± 4.6 mm Hg vs 38.5±6.4 mm Hg, P<0.01).Conclusion atRA inhibits MMP-1 overexpression and the accumulation of collagen, which might elicit favorable geometric remodeling in rat pulmonary hypertension induced by monocrotaline.
基金supported by the National Natural Science Foundation of China (20703030, 20871092)the Program for New Century Excellent Talents in University (NCET-08-0914)the Natural Science Foundation of Tianjin (10JCZDJC21600 and 10JCYBJC04800)
文摘Three new MOFs with the same components but different structures and magnetic behavior, {[Cu6(atr)6(H20)2(,u3- OH)2(SOa)5]'5.25H20}n (1), {[Cu2(atr)2(,t/-OH)2(SOa)].3H20}n (2), and {[CuT(atr)6(H20)6(fl3-OH)2(SOn)6].2H20}n (3) (atr= 4-amino-l,2,4-triazole), were respectively synthesized by diffusion reactions in the presence of different structure-directing agents. Complex 1 is a slightly spin-frustrated antiferromagnetic layer with sulfonate aggregated Cun6 clusters periodically ex- tended by ditopic sulfonate linkers. 2 is a grid-based coplanar sheet with hydroxyl group bridged -CuOCu- linear-chain inter- linked by pairs of p3-atr ligands, exhibiting strong antiferromagnetic interactions to lead to an S = 0 spin ground state at low temperature. In contrast, air-instable 3 has a ladder-like broad-ribbon structure constructed from triangular CuII3 cores and cen- trosymmetric CuII1 octahedra. Obviously, the variable Cun-ligand connectivity and the involving magnetic properties are sig- nificantly dominated by the cooperative and variable binding modes of the mixed sulfonate-atr ligands and bi-/tridentate bridging hydroxyl heterobridges.
基金supported by the Ministry of Science and Technology of China(2015CB910402)to Jiemin Wongthe National Natural Science Foundation of China(91419303)+1 种基金The Science and Technology Commission of Shanghai Municipality(14XD1401700,11DZ2260300)the National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”of China(2014ZX09507002-002)
文摘Histone methylation is believed to provide binding sites for specific reader proteins, which translate histone code into biological function. Here we show that a family of acidic domain-containing proteins including nucleophosmin (NPM 1), pp32, SET/TAF 113, nucleolin (NCL) and upstream binding factor (UBF) are novel H3K4me2-binding proteins. These proteins exhibit a unique pattern of interaction with methylated H3K4, as their binding is stimulated by H3K4me2 and inhibited by H3K4mel and H3K4me3. These proteins contain one or more acidic domains consisting mainly of aspartic and/or glutamic residues that are necessary for preferential binding of H3K4me2. Furthermore, we demonstrate that the acidic domain with sufficient length alone is capable of binding H3K4me2 in vitro and in vivo. NPM1, NCL and UBF require their acidic domains for association with and transcriptional activation ofrDNA genes. Interestingly, by defining acidic domain as a sequence with at least 20 acidic residues in 50 continuous amino acids, we identified 655 acidic domain-containing protein coding genes in the human genome and Gene Ontology (GO) analysis showed that many of the acidic domain proteins have chromatin-related functions. Our data suggest that acidic domain is a novel histone binding motif that can differentially read the status of H3K4 methylation and is broadly present in chromatin-associated proteins.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ19C200001)the Education Department of Zhejiang Province Scientific Research Project(No.Y201737925)+1 种基金the Zhejiang Provincial Key Laboratory for Chemical and Biological Processing Technology of Farm Products(No.2016KF0048)the Key Laboratory of Bioorganic Synthesis of Zhejiang Province(No.20170110),China
文摘Objective:This study aimed to clone and characterize the oxiranedicarboxylate hydrolase(ORCH) from Labrys sp.WH-1.Methods:Purification by column chromatography,characterization of enzymatic properties,gene cloning by protein terminal sequencing and polymerase chain reaction(PCR),and sequence analysis by secondary structure prediction and multiple sequence alignment were performed.Results:The ORCH from Labrys sp.WH-1 was purified 26-fold with a yield of 12.7%.It is a monomer with an isoelectric point(pl) of 8.57 and molecular mass of 30.2 kDa.It was stable up to 55℃with temperature at which the activity of the enzyme decreased by 50% in 15 min(T5015) of 61℃and the half-life at 50℃(t1/2,50℃) of 51 min and was also stable from pH 4 to 10,with maximum activity at 55℃and pH 8.5.It is a metal-independent enzyme and strongly inhibited by Cu2+,Ag+,and anionic surfactants.Its kinetic parameters(Km,kcat,and kcat/Km) were 18.7 mmol/L,222.3 s-1,and 11.9 mmol/(L s),respectively.The ORCH gene,which contained an open reading frame(ORF) of 825 bp encoding 274 amino acid residues,was overexpressed in Escherichia coli and the enzyme activity was 33 times higher than that of the wild strain.Conclusions The catalytic efficiency and thermal stability of the ORCH from Labrys sp.WH-1 were the best among the reported ORCHs,and it provides an alternative catalyst for preparation of L(+)-2,3-dihydrobutanedioic acid.
基金supported by the National Basic Research Program of China (Grant No.2006CB102102)National High Technology Research and Development Program (Grant No.2006AA10Z1D6)+1 种基金National Natural Science Foundation of China (Grant No.30800782)New Teacher Research Fund for the Doctoral Program of Higher Education (Grant No.20070504064)
文摘The association of the porcine Pitx2c gene with meat quality traits was investigated in the present study. A total of eight single nucleotide polymorphisms (SNPs) were found. Allele frequencies of four SNPs were further detected in four commercial breeds and eight Chinese indigenous breeds. Single SNP and meat quality associations were analyzed in a YorkshirexMeishan F2 population. The SNPs c.474C〉T (P〈0.01) and c.636C〉T (P〈0.05) showed a significant association with meat color (MCV1). The SNPs c,*37G〉A and c.*47G〉A were significantly associated with drip loss rate (DLR), water holding capacity (WHC) and meat color value (MCV1) consistently (P〈0.05). Linkage disequilibrium (LD) analysis revealed that the adjacent SNPs were in LD. Two major haplotypes were identified, and association analysis between haplotype combinations and meat quality indicated that the presence of two copies of haplotype 1 -CCGG- may improve meat quality.